In the top of the electrical compartment there is a "box". The water pump switch and outside light switch are mounted on the front of the box. The block heater outlet is mounted on the part of the box that faces the rear of the MH. So, you're looking at the edge of the outlet. The plate itself faces the rear of the MH and is rather hard to see the first time. A flashlight helps.
This is a copy and paste from TomSM on the RVForum.net where there is also a Winnebago forum.
2005 Journey 36G Deep Blue